The invention relates to high performance tires having a folded belt, a cur belt and an overlay wherein the folded belt has edges folded over both the cut belt and the overlay.
It is continually the goal of the tire industry to improve the performance of tires used in racing and on high performance stock automobiles. Desirable chamacteristics of such tins are lightweight, low drag, good traction, minimal runout, low noise, good handling, and low tradwear.
It is also a goal in the tire industry to engineer He constructions for specific conditions and uses. It has been found that optimizing handling using one construction, or high-speed durability using another construction, is possible.
It is the object of the present invention to provide lighter weight tires, which have improved or maintained physical properties. It is also an object of the invention to identify tire construction changes that alter the properties of a tire to optimize their use under different conditions. Other objects of the invention will be apparent from the following specification and claims.
EP 237,599 teaches polyaromatic amide fiber cords folded over a cut carbon fiber belt.
U.S. Pat. No. 4,644,988 teaches a folded glass belt structure in a tire.
Oare et al, in U.S. Pat. No. 5,115,853, and references cited therein, teach the use of overlays in tires. The references teach various materitals that can be used, and various gauges of such materials that are used in building tires, as well as various tire constructions.
Breny, in U.S. Pat. No. 5,437,321 teaches a high performance tire where an overlay is used in place of a cut belt, and a folded belt is folded over edges of the overlay.
Roesgen et al. in U.S. Pat. No. 5,332,018 teach a tire construction using a folded belt structure which comprises a folded belt, a cut belt, and an overlay, having some embodiments wherein the overlay is located between the folded edges of a folded belt.
Hubbell et al, in U.S. Pat. No. 5,323,829 teach a high performance tire having a folded belt structure wherein one embodiment comprise a folded belt folded over the edges of a cut belt, and an overlay covering the full width of a folded belt, including the folded over edges.
French Pat. 1,228,24 discloses a pneumatic fire having a folded belt structure (2) comprising one folded belt (5), a cut bell (4) and an overlay (6) disposed over a carcass ply (1), and tread rubber (3) disposed over the belt structure. Folded edges (5a) of folded belt (5) are folded over the edges of the cut belt (4) and overlay (6). xe2x80x9cBeltxe2x80x9d refers to plies of parallel cords, woven or unwoven, underlying the tead, unanchored to the bead, and having cord angles of from 17 to 27 degrees with respect to the equatorial plane of the tire. xe2x80x9cCut belt plyxe2x80x9d refers to a belt having a width less than the tread width which lies flat over the carcass plies in the crown area of the tire. xe2x80x9cCrownxe2x80x9d refers to that portion of the tire within the width limits of the tile tread in the area of the tire tread. xe2x80x9cCarcass plyxe2x80x9d refers to plies of parallel cords anchored to both beads of the tire. xe2x80x9cOverlayxe2x80x9d refers to fabric or fiber reinforced rubber having a width substantially equivalent to the tread width which is placed over the belt structure in a tire to minimize delamination at the belt edges and to provide a smoother ride. xe2x80x9cHigh Performance Automobilexe2x80x9d refers to stockcars that are designed for high speed such as Corvettes, LAborghini, Ferrari, Porsche, etc.
A pneumatic tire (10) comprises a pair of substan=aly parallel annular beads (12,12a), at least one reinforced carcass ply (14) wrapped around the pair of beads, a folded belt structure comprising at least one folded belt (22) and at least one cut belt (24) and an overlay (26) disposed over the at kast one carcass ply (14), tead rubber (18) disposed over the folded belt structure (22), and sidewalls (20) disposed between the beads (12,12a) and the tread rubber (18). In the illumed embodiment, the overlay (26) substantially covers edges of the cut belt (24) and is adjacent to the cut belt, and folded edges (22a,22b) of the folded belt (22) are folded over edges of the at least one cut belt (24) and the overlay (22).
The folded belt (22) may be reinforced with filaments or cords selected from the group consisting of fiberglass, aramid, carbon fibers, nylon, rayon, polyester, polyol, and mixtures thereof, and the cut belt (24) may be renforced with filaments or cords selected from the group consisting of steel, fiberglass, aramid, carbon fibers, nylon, rayon, polyester, polyol, and Cures thereof.
The overlay (26) is reinforced with filaments or cords selected from We group consisting of fiberglass, aramid, carbon fibers, nylon, polyester, polyol, and mixtures thereof.
In the illustrated embodiment, the overlay is cut overlay (30) (a single set of reinforced overlay material), although other types of overlay (30a), such as spiral overlay, and chopped overlay can be used.
An illustrated tire (10) of the invention has an aspect ratio of 0.45 to 0.55 and has a folded belt (22) and a cut belt (24) reinforced with fiberglass cords, and an overlay (26) reinforced with nylon cords.
Specific alternative tire constructions are described.